2'2 ANIMAL COMPETITORS 



bed-bug 1 , may do this; but the most common 

 agent is the flea. 



Another fact is that the rat seems especially 

 susceptible to the disease; and, indeed, it is be- 



MOUTII-PARTS OF A HAT-FLEA, SHOWING WHERE HACILLI MAY 



CI.1XO! AND BE CAKHIEl) INTO THE NEXT WOUND. 



From Doane's "Insects and Disease." By Permission of Henry 



Holt & Co. 



lieved that it was originally a disease of this 

 rodent. Bats abound in fleas, and, as is the 

 case with most furry or feathered animals, 

 have a species peculiar to their race. This 



